package com.jpyl.jpMedicalTreatment.util;

import java.security.MessageDigest;

/**
 * Created by dongbinbin on 2017/2/7.
 */
public class MD5Util {
    private static String byteArrayToHexString(byte b[]) {
        StringBuffer resultSb = new StringBuffer();
        for (int i = 0; i < b.length; i++)
            resultSb.append(byteToHexString(b[i]));

        return resultSb.toString();
    }

    private static String byteToHexString(byte b) {
        int n = b;
        if (n < 0)
            n += 256;
        int d1 = n / 16;
        int d2 = n % 16;
        return hexDigits[d1] + hexDigits[d2];
    }

    public static String MD5Encode(String origin, String charsetname) {
        String resultString = null;
        try {
            resultString = new String(origin);
            MessageDigest md = MessageDigest.getInstance("MD5");
            if (charsetname == null || "".equals(charsetname))
                resultString = byteArrayToHexString(md.digest(resultString
                        .getBytes()));
            else
                resultString = byteArrayToHexString(md.digest(resultString
                        .getBytes(charsetname)));
        } catch (Exception exception) {
        }
        return resultString;
    }

    private static final String hexDigits[] = { "0", "1", "2", "3", "4", "5",
            "6", "7", "8", "9", "a", "b", "c", "d", "e", "f" };
    /**
     * 使用MD5算法加密字符串
     * @param src 源字符串
     * @return 加密后的字符串
     */
    public static String encode(final String src) {
        String dest = new String(src);
        try {
            MessageDigest md = MessageDigest.getInstance("MD5");
            //进行加密,获取字节数组
            byte[] b = md.digest(dest.getBytes());
            dest = byte2hexString(b);
        } catch (Exception e) {
            e.printStackTrace();
        }
        return dest;
    }
    /**
     * 方法说明:把字节数组转换成字符串.
     * @param bytes
     * @return 字符串
     */
    protected static final String byte2hexString(byte[] bytes) {
        StringBuilder buf = new StringBuilder(bytes.length * 2);
        for (int i = 0; i < bytes.length; i++) {
            if ((bytes[i] & 0xff) < 0x10) {
                buf.append("0");
            }
            buf.append(Integer.toString(bytes[i] & 0xff, 16));
        }
        return buf.toString();
    }
}
